Generally, image forming apparatuses are known that are connected through a network, etc. to terminal apparatuses such as personal computers (PC) for image formation (printing) of image data transmitted from the terminal apparatuses. For example, when printing image data created with a terminal apparatus, a user operates the terminal apparatus to transmit a print instruction to an image forming apparatus. The image forming apparatus receives the print instruction, prints the image data from the terminal apparatus on a recording paper, and discharges a print having an image formed thereon into a predetermined paper discharge tray.
The user directly looks at the paper discharge tray of the image forming apparatus to check whether the print has been discharged in the paper discharge tray after the completion of the image formation. If discharged, the user takes out the print from the paper discharge tray to acquire the print. In this manner, when the user wants to know whether a print has been discharged in the paper discharge tray of the image forming apparatus, the user must directly look at the paper discharge tray at all times or any timing, which is a cumbersome operation for the user.
On the other hand, if a user forgets to remove a print from the paper discharge tray, the print will be left in the paper discharge tray for a prolonged time. Therefore, if a malicious third party exists, the third party may peep at contents of the left print or take away the print, which increases the risk of leakage of important information. Furthermore, If an allowable amount of discharged paper is exceeded in the paper discharge tray, an accumulation amount detecting portion detects the excess to discontinue the printing, and therefore, if the left prints are accumulated, the amount thereof eventually exceeds the allowable amount of discharged paper in the paper discharge tray as above and causes problems such as discontinuation of the printing.
In a conventionally known method of technology for notification of prints forgotten to be taken out, a paper discharge tray is provided for each user, and if a print is left for a predetermined time after the print is discharged into each paper discharge tray, a user corresponding to the paper discharge tray is notified that a print is left. However, in this method, the number of the paper discharge trays needs to be the same as the number of users and it is problematic that the size of the image forming apparatus must be increased to support a multiplicity of users. If the image forming apparatus is implemented without increasing the size thereof, it is problematic that the use of the image forming apparatus is limited to a small number of users corresponding to a small number of the paper discharge trays.
With regard to the above problems, for example, Japanese Laid-Open Patent Publication No. 2000-155506 describes an image forming apparatus not increasing the size of the apparatus configuration and capable of being utilized by a multiplicity of users and the image forming apparatus includes a forgotten print notification function so as not to leave prints for a long time. This image forming apparatus includes an image forming portion that forms images of image data from a PC and an identification code of a user who uses the PC, a placing tray that temporarily places a print having an image formed thereon by the image forming portion, a document reading portion that reads the identification code on the print placed on the placing tray, a transfer device that transfers the print to the document reading portion, and a notifying portion that notifies the PC to cause the user executed the image forming operation to remove the print based on the identification code read by the document reading portion.
However, in the case of the image forming apparatus described in Japanese Laid-Open Patent Publication No. 2000-155506, since the conveying device must be included to convey the prints (in the placing tray) to the reading portion, it is problematic that the apparatus configuration is complicated and increased in size, especially in a reading mechanism.
Moreover, a paper sheet must always be discharged such that a surface with an ID image printed faces upward. However, the print surface of the ID image may face downward due to a paper discharge tray and output conditions such as one-side printing, two-side printing, face-up paper discharge, and face-down paper discharge. For example, if the one-side printing and the face-down paper discharge are specified, if an ID image is printed on the same surface as a print surface of an image, the ID image print surface faces downward when discharged. In this case, it is difficult to read the ID image with the reading portion.